Chain of custody Procedures to account for the integrity of each urine specimen or aliquot, by tracking, handling, and storing from point of specimen collection to the final disposition of the specimen. Documentation of this process must include the date and purpose each time a specimen or aliquot is handled or transferred and ID of each individual in the chain of custody. Commerce An interchange of goods or commodities. Commercial motor vehicle A commercial vehicle with a gross vehicle weight rating of 26,001 or more pounds or is designed to transport 16 or more occupants (to include the drive or is of any size and is used in the transport of hazardous materials that require the vehicle to be placarded. Confirmation The process of using an analytical procedure to identify the presence of a specific drug or metabolite that is independent of an initial test and which uses a different technique and chemical principle from that of an initial test in order ensure reliability and accuracy.